A conventional camshaft miller of this kind is provided with a work support device for supporting an intermediate portion of a work (camshaft) to be machined having both ends clamped for enabling the mill-machining with high accuracy.
The conventional work support device of the character described above includes, as shown in FIG. 1 and FIG. 2 being a sectional view taken along the line II--II in FIG. 1, respectively two supporting portions d for supporting, from a lower side thereof and a direction reverse to a milling direction, a plurality of journal portions c being at intermediate portions of a work b which is clamped at its both ends by chucks a, thereby preventing the work b from being deformed and vibrated by the milling reaction force during the milling operation.
The conventional camshaft support device of the above kind is disposed to be movable along an axial direction of the work b rested on a bed, not shown, to adjust an axial height (which means a distance from the supporting surface of the supporting portion d to the center of the work b, and the adjustment thereof is performed by changing the height of the supporting portion) in conformity with a diameter, of a portion having a smaller error within tolerance, of the journal portion c. For this reason, in a case where the work b on a side of the journal portion having a larger error within the tolerance of the journal portion c is clamped between the chucks a and a, certain supporting portions d, for example, those on both end sides, lift upward the work b, and accordingly, the work b is deformed as shown in FIG. 1 and a gap e is formed as shown in FIG. 2 between the journal portion c and the supporting surface of the supporting portion d at the central portion of the camshaft. As a result, there causes a case where the work b is not supported at the central portion of the camshaft, resulting in generation of vibration and noises during the machining and hence degrading the machining accuracy, thus being inconvenient.
Therefore, an object of the present invention is to provide a work support device of a camshaft miller capable of supporting a work without being effected by a difference in an error within tolerance of a diameter of a journal portion of a camshaft and hence being capable of preventing vibrations and noises from being generated during a machining operation to thereby prevent the lowering of the machining accuracy.